Except for the pigeon thing at the end of the trailer, Iron Sky is a good looking film:

The basic premise is that at the end of WW2, the Nazis launched a mission to the moon. This is not too infeasible given the V2 technology (a lot of Nazi scientists were employed by NASA after WW2). It would have been better with V2-type launch vehicles, but let's not get picky.

The Nazis made a base on the far side of the moon, where they built and developed their technology. Again, not too infeasible given that we can't see the far side from Earth, and we have only limited surveys of that side.